A thin film transistor liquid crystal display (TFT-LCD) is one of Active Matrix-LCD's (AM-LCD's). TFT-LCD has advantages on lightness, contrast, energy consume, life cycle, volume and weight. It is highly automatic, low-cost, and suitable for mass production, and it becomes a main product in new century with wide development space. TFT-LCD is formed by cell-assembling a TFT substrate and a color substrate (CF) and filling crystal. To protect the crystal from the contamination of outside environment, a frame sealant has been used to seal the TFT-LCD.
Current frame sealants are mainly classified as thermo-curable one and UV curable ones. The UV curable frame sealant has a short curing time and is fast for curing, but has poor controllability. Moreover, it is not suitable for special display modes, such as polymer dispersed liquid crystals (PDLC) or polymer stabilized cholesteric texture liquid crystals (PSCT), because a polymeric monomer sensitive to UV is contained in the liquid crystal cell, which can be sealed only through the thermo-curable frame sealants. Current thermo-curable frame sealants employ an external heat source, resulting in slow curing, long curing time, large energy lost, and a heat conduction gradient from external towards internal occurring during the process of curing. Moreover, current thermo-curable frame sealants are problematic in some aspects, such as uneven sealant breadth, retraction, and breakage. Defective curing would directly affect the quality of the panel, for example, poorly cured panel would present lightness mura in periphery. Therefore, there is a need for an improved thermo-curable frame sealant.